#brobots school meal tracking

This is a system running on Raspberry Pi that helps to record at what exact time each student has taken his meal. It uses personal RFID tags as user identifiers.

Hardware

• Raspberry Pi 3B+
• RDM6300 RFID Reader - 125kHz
• RFID wrist tags - 125kHz

Software

• Python as main project language
• Google Sheets API as data storage
  • I'd personally use MySQL for these purposes, but all school data is stored in Google Sheets API - @andrewyazura
• RDM6300 sensor library

Setup

Environment variables

• ENVIRONMENT
  • DEVELOPMENT - app will use .env.dev
  • PRODUCTION - app will use .env

Configuration and authentication

1. Create a new Google Cloud Platform (or use an existing one) project. Enable Google Sheets API and create a service account for this device. Read this manual on how to get it: Creating a service account. Next, download a JSON key for that service account.
2. Create a Google Sheets document where your data will be stored.
   • Give your service account access to the document. Just copy email address of service
3. Insert data into .env file
   • Copy example from .env.example
   • Set DOCUMENT_ID to ID of a document you created
   • Set SERVICE_ACCOUNT to a path to JSON key you downloaded

How to get service-account.json

Follow this steps:

• Go to Credentials tab
• Open Manage service accounts link
  • It's located near Service Accounts list
• Find the service account you need.
• Press Actions button (three dots) and choose Create key
• Choose JSON and press Create

Google Sheets document setup

Copy this example: link.

If for some reason the link isn't working, here is how table looks:

IDs	Users		Records
1	user1	---	1970/01/01 00:00:00
2	user2	---	1970/01/01 00:00:00	1970/01/01 00:00:00
3	user3	---
4	user4	---	1970/01/01 00:00:00

New records are appended into user's row. Record only has date and time of the request.

Raspberry Pi setup

Serial / UART

Run sudo raspi-config. Select Interfacing Options / Serial then disable Serial console and enable Serial hardware. Now use /dev/serial0 in any code which accesses the Serial Port.

If given instructions didn't work, try using this tutorial: link.

System Service Unit

You can use mealtracker.service that is provided in the repostitory or write your own unit. If you're using the existing one, you have to:

1. Enter path to your project in specified placed
2. Enter name of the user you're going to use
   • On the Raspberry Pi it's most probably pi user.
3. Copy the unit file to /etc/systemd/system/

Now the service is accessible over sudo systemctl command.

Remember to stop the service before using input.py

Usage

sudo systemctl start mealtracker.service - start the service

sudo systemctl stop mealtracker.service - stop the service

sudo systemctl status mealtracker.service - check status of the service

Custom Service

Here is a link to official Raspberry Pi documentation on writing services: link